The above example returns the original arguments (after your customizations) back to the parent class, so it can continue with its normal operations.

Creating Instances

Once you have defined a class, you can create new instances of that
class by calling its create() method. Any methods, properties and
computed properties you defined on the class will be available to
instances:

Note that for performance reasons, while calling create() you cannot redefine an instance's
computed properties and should not redefine existing or define new methods. You should only set simple properties when calling
create(). If you need to define or redefine methods or computed
properties, create a new subclass and instantiate that.

By convention, properties or variables that hold classes are
PascalCased, while instances are not. So, for example, the variable
Person would point to a class, while person would point to an instance
(usually of the Person class). You should stick to these naming
conventions in your Ember applications.

Initializing Instances

When a new instance is created, its init() method is invoked
automatically. This is the ideal place to implement setup required on new
instances:

If you are subclassing a framework class, like Ember.Component, and you
override the init() method, make sure you call this._super(...arguments)!
If you don't, a parent class may not have an opportunity to do important
setup work, and you'll see strange behavior in your application.

Arrays and objects defined directly on any Ember.Object are shared across all instances of that class.